While co-location enables better collaboration, chartering enables better planning, focus and alignment. Once a community has done the hard work of articulating a clear vision, mission and objectives, and the charter has been approved by the people funding the work, the community knows why it exists and what it needs to achieve. Given any piece of work, people in the community can ask, “Does this further the work of achieving our charter?”
Customer feedback should be brought in as soon as possible. Show them a mockup, show them a sketch on a napkin, or simply ask them questions. Products are built for the user, not for the product team. In agile, accountability is key, and everyone, including the development team, is responsible for validating work.